1. The Field of the Invention
The present invention relates generally to semiconductor device testing during fabrication. More particularly, the present invention relates to a system and method that employs a cleaning wafer for in-line cleaning of probe pins on a probe card used in testing semiconductor devices during fabrication.
2. The Relevant Technology
During fabrication of semiconductor devices from silicon wafers, a prober machine is used to interface a semiconductor device to a tester machine while still in wafer form prior to cutting the wafer into individual chips. A typical prober machine includes a probe card having an array of probe pins that contact bond pads on the semiconductor device during testing. The bond pads on the semiconductor device are made from metallic materials such as aluminum which can oxidize when exposed to air. Also, organic material left over from certain fabrication processes can be disposed on the bond pads. When probe pin tips repeatedly contact bond pads on a silicon wafer, metal oxides such as aluminum oxides and other materials on the bond pads can build-up on the probe pin tips, thereby interfering with the function of the probe pins during testing operations. Thus, it becomes necessary to periodically clean the probe pins on a probe card.
In conventional cleaning operations, a probe maintenance station is utilized in order to clean probe pins on a probe card used in testing fabricated semiconductor devices. This requires the removal of the probe card from the production line in order to clean the probe pins, resulting in a certain amount of production downtime. The production downtime includes the time to remove the probe card from the prober, and the time to install and perform a complete new set up for a clean probe card. Also, additional time is spent in taking the dirty probe card to a hardware support facility, in cleaning/aligning, and documenting the probe card, and in getting the cleaned probe card back to production personnel.
As manufacturing techniques have improved, it has become possible to probe more semiconductor dies in parallel at one time, requiring increasingly wider probe card arrays. This has resulted in ever increasing difficulty and downtime in order to have the probe card arrays taken off-line, to replace the probe card arrays, and then to bring the system back online, as well as additional time to clean the removed probe card arrays and bring the arrays back into service. While various ceramic burnishing chucks have been used in the past to clean probe tips, such as separate chucks with a piece of ceramic thereon for the probes to touch down on for cleaning, such conventional burnishing chucks are too small for the wider probe cards currently used.
Accordingly, there is a need for improved probe pin cleaning systems and methods that overcome or avoid the above problems.